Rare earths (RE) have been used to improve the high temperature oxidation resistance of low alloy steel containing elements like Cr, Al, V and Mo. Further, the RE can be added either to the alloy or by applying as an oxide coating to the alloy surface. In this study the high temperature oxidation resistance of rare earth (RE) oxide coated 1Cr-0.3Mo-0.25V alloy was determined. This paper presents the influence of surface additions of nano-crystalline oxides CeO2 on the isothermal oxidation behavior of 1Cr-0.3Mo-0.25V alloys at temperatures ranging from 600 °C to 900 °C. The oxidation rate of RE oxide coated1Cr-0.3Mo-0.25V was significantly lower than that of the uncoated alloy. The improvements in oxidation resistance are the reduced oxidation rates and the increased oxide scale adhesion. Scanning electron microscopy (SEM), X-ray diffractometry (XRD), and electron probe micro analyzer (EPMA) were employed for these analyses. The scale formed in the presence of RE oxides was very thin, fine grained and adherent.

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Incremental forging processes like radial forging become more and more crucial in industry due to their outstanding economic performance, their high flexibility and their advantageous compressive stress states. However, nowadays a basic method to analyze forging processes, FEM simulation is still a very time consuming procedure and needs complex models to implement incremental processes. Especially long term studies with focus on tool temperature development during several hours of production cannot be performed with classical FEM models for radial forging. The main problem in modelling is the high operating frequency of the forging devices, which leads to small necessary time steps and, therefore, to inacceptable calculation time due to numerous simulations that have to be run to complete a cogging process sequence. Steady state in die temperature is often only reached after processing several workpieces. Hence, it is necessary to use a simplified FE-model of the forging process to predict the steady state temperature of the forging dies. In the present work a simplified FE-model is established to investigate the steady state temperature of the dies. This approach is verified by metallographic studies proving its accuracy.

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